OmpW and OmpV are required for NaCl regulation in Photobacterium damsela

Photobacterium damsela is a marine pathogen to both fish and human beings. The bacterium can shift between the ambient seawater and hosts, suggesting the existence of proteins rapidly responding to salt concentration. In the current study, proteomic methodologies were applied to screen the outer membrane proteins (OMPs) related to salt stress. OmpW and OmpV were determined in the response in this bacterium as OmpC and OmpF did in E. coli. Furthermore, the two genes were overexpressed in E. coli Top10F and complemented in V. paraheamolyticus mutants. The ability in salt-tolerance was elevated in the E. coli overexpressed OmpW and reduced in the cells overexpressed OmpV. These V. paraheamolyticus mutants could recover their response to environmental salt concentration when they were complemented by P. damsela OmpW and OmpV. These findings indicate that OmpW and OmpV are required for environmental salt regulation in P. damsela, in which OmpW and OmpV, respectively, elevate and reduce the ability in salinity-tolerance.